To original poster, assuming I understand correctly, ... yup, reasonable request to selectively 'copy' a given scene from one OBS Scene Collection to another... just not an option with current OBS menu/tools :(
In Ideas and Suggestion you can find a long running discussion (multi-year) of being able to selectively copy 'n paste Scene/Source items between Scene Collections. And that discussion explains why it such a capabilities is NOT available at this point. One option folks have mentioned is manually going into the associated settings file (JSON, iirc) and hand editing the file with the 'scene' you want (ie copy between collections), being careful regarding any groupings, references, etc that could screw things up.
FYI - I've been doing our HoW stream for 7+ months now. My Scene list for a service is over 25 at this point. And using PowerPoint for Service Bulletin. So my scenes are largely static, and I simply update the pre-recorded Media (video) Source to point to this weeks content (usually 8-10 videos between readings, music, announcements, etc)
- there are plug-ins that could automate this. Or I could use same filename (Prelude, Postlude, etc) but simply running though Scenes and updating Media sources is easy enough and need to play content in advance anyway.. so negligible benefit to automate, and less plug-ins usually is more stable
This is a keep-it-simple approach. I'm not using lower thirds, and lyrics that update /scroll during performance... rather lyrics in bulletin on left side of screen (PPTx Window capture), video on right side. easy peasy